Kinematic and Kinetic Comparison of Sprint-Specific Exercises: Impact on Maximal Sprint Acceleration Training

Abstract

Sprint-specific exercises (SSEs) are believed to train force, power and/or velocity qualities involved in the acceleration phase of sprinting. However, the kinetics and the kinematics of such exercises have never been explored. The aim of this study was to compare mechanical variables (horizontal and vertical forces, horizontal velocity of the centre of mass and the ratio of force) between SSEs and an all-out 40-m sprint acceleration (Sref). These variables were measured over each situation (Sref and 14 SSE) using six track-embedded force plates. The horizontal forces and velocities were either lower or equal to those of the Sref (SSE grand average deviation from FVP ~ -0.29 N∙kg^-1 for force; SSE grand average from Sref ~ -0.14 m∙s^-1 for velocity), while vertical force output was mostly greater in the SSE than the Sref (SSE mean deviation from Sref ~0.49 N∙kg^-1). The ratio of force was lower or equal for the SSE compared to Sref. Despite large inter-individual variability, these SSEs seem useful to stimulate vertical force production, and not horizontal as hypothesised by coaches. These results suggest the importance of analysing the SSE used during training, from a force-velocity point of view, to better characterize their effectiveness.

Keywords: categorisation; mechanics; running; training.

Figure 1

Comparison of mean horizontal force production (F_ymean N∙kg⁻¹) between the SSEs and the Sref. Graph represents the mean horizontal force production over the 6.60 m of force plates (F_ymean N∙kg⁻¹); values are means of all participants. In black, there are values that differed significantly between the SSE and the 40-m sprint reference (Sref); * significant difference at p < 0.05; ** significant difference at p < 0.01; the dotted line shows the number of participants for whom values during the SSE were above the Sref value; tripod bouncing stride start (BSS), hop 2 (H2), hands-on-the ankle start (HA), hands-on-the knee start (HK), hands-on-hips start (HH), plinth start (PL), slider start (SL), medicine ball push (MP), plyometric action + medicine ball push (PMP), backward jump + forward sprint (BJF), sideways knee raises over studs (50 cm) + forward sprint (KR50), sideways knee raises over studs (20 cm) + forward sprint (KR20), sideways jump over studs + forward sprint (SIJ) and push-up start (PUS)

Figure 2

Comparison of mean vertical force production (F_zmean N∙kg⁻¹) between the SSE and the Sref. Graph represents the mean vertical force production over the 6.60 m of force plates (F_zmean N∙kg⁻¹); values are the means of all participants. In black, there are values that differed significantly between the SSE and the 40-m sprint reference (Sref); * significant difference at p < 0.05 with the Sref; the dotted line shows the number of participants for whom values during the SSE were above the Sref value; tripod bouncing stride start (BSS), hop 2 (H2), hands-on-the ankle start (HA), hands-on-the knee start (HK), hands-on-hips start (HH), plinth start (PL), slider start (SL), medicine ball push (MP), plyometric action + medicine ball push (PMP), backward jump + forward sprint (BJF), sideways knee raises over studs (50 cm) + forward sprint (KR50), sideways knee raises over studs (20 cm) + forward sprint (KR20), sideways jump over studs + forward sprint (SIJ) and push-up start (PUS)

Figure 3

Comparison of mean horizontal velocity (V_ymean m∙s⁻¹) between the SSE and the Sref. Graph represents the mean horizontal velocity over the 6.60 m of force plates (V_ymean m∙s⁻¹); values are means of all participants. In black, there are values that differed significantly between the SSE and the 40-m sprint reference (Sref); *significant difference at p < 0.05; ** significant difference at p < 0.01 with the Sref; the dotted line shows the number of participants for whom values during the SSE were above the Sref value; tripod bouncing stride start (BSS), hop 2 (H2), hands-on-the ankle start (HA), hands-on-the knee start (HK), hands-on-hips start (HH), plinth start (PL), slider start (SL) and medicine ball push (MP)

Figure 4

Comparison of the mean ratio of force (RF_mean%) between the SSE and the Sref. Graph represents the mean ratio of force over the 6.60 m of force plates (RF_mean%); values are means of all participants. In black, there are values that differed significantly between the SSE and the 40-m sprint reference- (Sref); ** significant difference at p < 0.01; *** significant difference at p < 0.0001 with the Sref; the dotted line shows the number of participants for whom values during the SSE were above the Sref value; tripod bouncing stride start (BSS), hop 2 (H2), hands-on-the ankle start (HA), hands-on-the knee start (HK), hands-on-hips start (HH), plinth start (PL), slider start (SL), medicine ball push (MP), plyometric action + medicine ball push (PMP), backward jump + forward sprint (BJF), sideways knee raises over studs (50 cm) + forward sprint (KR50), sideways knee raises over studs (20 cm) + forward sprint (KR20), sideways jump over studs + forward sprint (SIJ) and push-up start (PUS)